The invention relates in general manner to vibratory systems. The invention also relates to vibratory machines for screening materials and/or for feeding materials, which machines include vibratory systems.
Vibratory systems are known in the state of the art that comprise two unbalanced shaft lines. Each unbalanced shaft line has a rotary shaft and an unbalance module constrained to rotate with said shaft. The shaft lines are driven in rotation so as to generate vibration for use in screening materials and/or for causing them to advance.
Nevertheless, driving rotation of unbalanced shaft lines in the systems known in the state of the art requires a large amount of energy. In addition, when stopping rotary drive, the vibration frequencies that are generated may include values that correspond to resonant frequencies of certain portions of the machine. In particular, the frequency of vibration may come close to the resonant frequency of damper elements on which the frame of the machine is mounted.